The BCAAs (Branch Chain Amino Acids) are leucine, isoleucine, and valine. The name "branched-chain amino acids" is derived from the structure of these compounds. Each one has a forked outcropping that looks a bit like a branch, hence the name branched chain amino acids.

The three BCAAs are incredibly essential and actually fall into the category of essential amino acids. Essential amino acids are amino acids that the body cannot synthesize on its own and therefore must get adequate amounts through dietary sources.

In fact, even though there are about 20 amino acids that the muscles use for growth, the BCAAs comprise roughly a third of the aminos within muscle tissue. So if muscle growth is your goal BCAAs are a must.